Performance Analysis of Constrained Loosely Coupled GPS/INS Integration Solutions

The paper investigates approaches for loosely coupled GPS/INS integration. Error performance is calculated using a reference trajectory. A performance improvement can be obtained by exploiting additional map information (for example, a road boundary). A constrained solution has been developed and its performance compared with an unconstrained one. The case of GPS outages is also investigated showing how a Kalman filter that operates on the last received GPS position and velocity measurements provides a performance benefit. Results are obtained by means of simulation studies and real dat

The Ginninderra CH4 and CO2 release experiment: An evaluation of gas detection and quantification techniques

A methane (CH4) and carbon dioxide (CO2) release experiment was held from April to June 2015 at the Ginninderra Controlled Release Facility in Canberra, Australia. The experiment provided an opportunity to compare different emission quantification techniques against a simulated CH4 and CO2 point source release, where the actual release rates were unknown to the participants. Eight quantification techniques were assessed: three tracer ratio techniques (two mobile); backwards Lagrangian stochastic modelling; forwards Lagrangian stochastic modelling; Lagrangian stochastic (LS) footprint modelling; atmospheric tomography using point and using integrated line sensors. The majority of CH4 estimates were within 20% of the actual CH4 release rate (5.8 g/min), with the tracer ratio technique providing the closest estimate to both the CH4 and CO2 release rates (100 g/min). Once the release rate was known, the majority of revised estimates were within 10% of the actual release rate. The study illustrates the power of measuring the emission rate using multiple simultaneous methods and obtaining an ensemble median or mean. An ensemble approach to estimating the CH4 emission rate proved successful with the ensemble median estimate within 16% for the actual release rate for the blind release experiment and within 2% once the release rate was known. The release also provided an opportunity to assess the effectiveness of stationary and mobile ground and aerial CH4 detection technologies. Sensor detection limits and sampling rates were found to be significant limitations for CH4 and CO2 detection. A hyperspectral imager\u27s capacity to image the CH4 release from 100 m, and a Boreal CH4 laser sensor\u27s ability to track moving targets suggest the future possibility to map gas plumes using a single laser and mobile aerial reflector

Patterns of change and stability in the gender division of household labour in Australia, 1986-1997

Recent research in Australia and overseas has suggested that we are witnessing a convergence of men's and women's time on domestic labour activities. But there is disagreement about whether this is due to women reducing their time on housework or men increasing their time on housework. This article addresses these issues using national survey data collected in Australia in 1986, 1993 and 1997. The results show some changes in the proportional responsibilities of men and women in the home with men reporting a greater share of traditional indoor activities. But overall both men and women are spending less time on housework. In particular, women's time on housework has declined by six hours per week since 1986. Hence, while the gender gap between men's and women's involvement in the home is getting smaller, it is not the result of men increasing their share of the load, but is due to the large decline in women's time spent on domestic labour. There is also evidence of change in the relationship. between paid and unpaid work for women. Women's hours of,paid labour had a greater impact on their involvement in domestic labour in 1997 compared to a decade earlier. The article concludes that women's increased labour force involvement in combination with changing patterns and styles, of consumption is leading to some changes in the gender-division:of household labour, but not in the direction anticipated by earlier commentators on the domestic division of labour

Development of a Protective Enclosure for Remote Sensing Applications—Case Study: Laser Scanning in Underground Coal Mines

Sensing for equipment location and mapping in explosion risk zones such as underground coal mines is a difficult proposition due to the regulatory requirement for certified protective enclosures to safely house the required complex electrical equipment. This paper provides a case study for the process involved in creating and implementing an optical-grade enclosure for use in these environments. The result of this process has been the creation of ExScan®, a 3D laser mapping system that is providing step-change capability for remote operations and automation in the underground coal mining industry

Remote monitoring of subsurface heatings in opencut coal mines

The detection and monitoring of spontaneous combustion (sponcom) events in opencut coal mines are significant hazard management issues. Currently, the only way of locating sponcom incidents is by manual inspection, whether by visual examination or by use of hand-held thermal cameras, often putting personnel at risk. These inspections are also limited in terms of access and coverage. Therefore, there is a need to implement a convenient remote means to detect and monitor the state of subsurface heatings in opencut coal mines over extended areas for significant periods of time. A versatile self-contained imaging system has been developed that is deployed using an unmanned aerial vehicle. The system eliminates the safety hazard of personnel accidentally entering hot ground and being exposed to toxic gases often associated with heatings. Results obtained from the imaging system is presented, which generates thermal and visible geo-referenced images that can be overlaid onto a digital map of the surveyed area. The data allow rapid detection and accurate localisation of anomalous heat levels within target areas that can be updated on the mine plan for management purposes, and thus enables mitigation strategies to be monitored for effectiveness

Initial tests on a microwave monitor for industrial fluidized beds

Preliminary work on development of a microwave unit to monitor the state of industrial fluidized beds is reported. A 10.7 GHz microwave motion detector unit has been fitted with metered output and an audio system that enables an operator to obtain both visual and aural information on bed performance. This unit clearly detects and measures bubbling activity in a model fluidized bed. Performance compares favourably with a pressure fluctuation technique

The Ginninderra CH4 and CO2 release experiment : an evaluation of gas detection and quantification techniques

A methane (CH4) and carbon dioxide (CO2) release experiment was held from April to June 2015 at the Ginninderra Controlled Release Facility in Canberra, Australia. The experiment provided an opportunity to compare different emission quantification techniques against a simulated CH4 and CO2 point source release, where the actual release rates were unknown to the participants. Eight quantification techniques were assessed: three tracer ratio techniques (two mobile); backwards Lagrangian stochastic modelling; forwards Lagrangian stochastic modelling; Lagrangian stochastic (LS) footprint modelling; atmospheric tomography using point and using integrated line sensors. The majority of CH4 estimates were within 20% of the actual CH4 release rate (5.8 g/min), with the tracer ratio technique providing the closest estimate to both the CH4 and CO2 release rates (100 g/min). Once the release rate was known, the majority of revised estimates were within 10% of the actual release rate. The study illustrates the power of measuring the emission rate using multiple simultaneous methods and obtaining an ensemble median or mean. An ensemble approach to estimating the CH4 emission rate proved successful with the ensemble median estimate within 16% for the actual release rate for the blind release experiment and within 2% once the release rate was known. The release also provided an opportunity to assess the effectiveness of stationary and mobile ground and aerial CH4 detection technologies. Sensor detection limits and sampling rates were found to be significant limitations for CH4 and CO2 detection. A hyperspectral imager's capacity to image the CH4 release from 100 m, and a Boreal CH4 laser sensor's ability to track moving targets suggest the future possibility to map gas plumes using a single laser and mobile aerial reflector